In case of Young experiment

Options

A. There are two virtual source of light from same monochoromatic source of light
B. Both the slits get light from the single monochromatic source of light
C. Two separate monochromatic sources of light of same wavelength are used
D. None of these

Answer

### Step-by-Step Solution:

1. **Understanding Young's Double Slit Experiment**:
- In Young's experiment, two slits are used to create an interference pattern on a screen. The light from these slits creates alternating bright and dark fringes due to constructive and destructive interference.

2. **Identifying the Sources of Light**:
- The question mentions two sources of light. In Young's experiment, it is crucial that these sources are coherent, meaning they must have the same frequency and a constant phase difference.

3. **Evaluating Option 1**:
- The first option states that there are two virtual sources of light. In reality, Young's experiment uses two real sources (the two slits act as sources of light). Therefore, this option is incorrect.

4. **Evaluating Option 2**:
- The second option states that both slits receive light from a single monochromatic source. This is true because for sustained interference, both slits must be illuminated by the same source of light to ensure they are coherent. Thus, this option is correct.

5. **Evaluating Option 3**:
- The third option mentions using two separate monochromatic sources of light of the same wavelength. However, if these sources are separate, they may not maintain a constant phase difference, leading to incoherence. Hence, this option is incorrect.

6. **Conclusion**:
- Based on the evaluations, the correct answer is option 2, which states that both slits get light from a single monochromatic source of light.